{"id":"CVE-2026-34873","details":"An issue was discovered in Mbed TLS 3.5.0 through 4.0.0. Client impersonation can occur while resuming a TLS 1.3 session.","modified":"2026-07-15T01:48:54.015858909Z","published":"2026-04-01T00:00:00Z","related":["openSUSE-SU-2026:10498-1"],"database_specific":{"unresolved_ranges":[{"source":"DESCRIPTION","extracted_events":[{"introduced":"3.5.0"},{"fixed":"4.0.0"}]}],"cna_assigner":"mitre","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34873.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34873.json"},{"type":"ADVISORY","url":"https://mbed-tls.readthedocs.io/en/latest/security-advisories/"},{"type":"ADVISORY","url":"https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-client-impersonation-while-resuming-tls13-session/"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34873"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mbed-tls/mbedtls","events":[{"introduced":"1ec69067fa1351427f904362c1221b31538c8b57"},{"fixed":"0bebf8b8c7f07abe3571ded48a11aa907a1ffb20"},{"introduced":"ec4044008d2d069da38288bc76b0fee34ec78646"},{"fixed":"0fe989b6b514192783c469039edd325fd0989806"}],"database_specific":{"extracted_events":[{"introduced":"3.5.0"},{"fixed":"3.6.6"},{"introduced":"4.0.0"},{"fixed":"4.1.0"}],"source":"CPE_RANGE","cpe":"cpe:2.3:a:trustedfirmware:mbed_tls:*:*:*:*:*:*:*:*"}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34873.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"}]}